The increasing popularity of the World Wide Web and other Internet-based applications has encouraged many software companies and corporations to allocate major resources towards web-enabling existing or new applications. For example, most retail applications conducted solely by phone or face-to-face in the past are now also conducted electronically over the World Wide Web.
Several approaches are used by web application developers to develop web applications. Each web application generally consists of the application framework, the application graphical user interface (GUI), application event handler(s) and the application business logic. A first approach initiates with graphic designers and/or business analysts specifying web application screens in Hypertext Markup Language (HTML) format using visual HTML editors such as Microsoft FrontPage, Netscape Composer and Adobe GoLive. The resulting HTML files are then given to web developers who specialize in computer programming. The web developers choose a traditional programming language such as C, C++, or Perl, prepare the programming source code files and embed the HTML tags from the HTML files provided by the graphic designers/business analysts directly into the web application programming source code. The web developers must also write the application framework and event handler code. All application source code files are then compiled into executable objects that are later installed within a web application server for access by web browsers.
However, after the web developers embed the HTML tags into the application source code, it is difficult for the graphic designers/business analysts to visualize how the web application screens appear by analyzing the HTML tags intermixed with the programming language code. As a result, modifying or changing the graphical user interface is difficult after the initial development. Further, each graphical user interface modification requires the web developers to re-compile the application source code and reinstall the object code within the web application server. Finally, the web developers must manually write the application framework and event handler code, which is a complex task and often introduces errors into the web application.
A second approach also initiates with graphic designers and/or business analysts specifying web application screens in HTML format using a visual HTML editor. The resulting HTML files are then given to web developers who specialize in computer programming. However, instead of using a traditional programming language such as C, C++ or Perl to write the web application, the web developers write scripting language code such as JavaScript, VBScript, PHP Hypertext Preprocesor (PHP) or ColdFusion directly into the HTML files. All application code files are later interpreted at runtime based on a web request.
However, because of the scripting nature of the programming language, it is difficult for web developers to write structural or object-oriented code. Also, the final application source code includes many different HTML files whose structure and naming system do not reflect the purpose of the code residing inside them. Further, it is difficult for web developers to add functionality using this approach. Finally, since most scripting languages are interpreted at runtime based on a web request, the runtime performance of the web application is much slower than for a compiled web application.
A third approach, the Enhydra XMLC compiler introduced by Lutris Technologies, initiates with graphic designers and/or business analysts specifying web application screens in either HTML, Website Markup Language (WML) or Extensible Markup Language (XML) format. The resulting files are then converted by the XMLC compiler into a Java class containing an industry standard Document Object Model (DOM) tree. This DOM tree is a collection of Java objects that allows web developers to remove, update or add new content to the DOM tree. Also, this conversion separates the input files into an XML class that the graphic designers/business analysts can manipulate, separate from the web developers preparing the application framework and business logic. Thus, graphic designers/business analysts can view and test the application screens as a standalone component, while web developers prepare the application source code.
However, the Enhydra XMLC compiler does not generate application framework code or event handier code, nor does it generate any type of skeleton for the application framework or event handler methods to assist the web developers. In fact, the DOM object tree requires further manipulation by the web developers, including setting all attributes, to convert the DOM object tree into a “string” which is readable by a web browser within the Transmission Control Protocol/Internet Protocol (TCP/IP). Thus, the Enhydra XMLC Compiler approach relies on the web developers to write the application framework code, event handler code, and develop the code for displaying outputs using the generated DOM object tree. Further, after the initial files created by the graphic designers/business analysts are compiled by the XMLC compiler, any changes to the web application screens by the graphic designers/business analysts must be manually re-compiled by the web developers before the web application is available based on a web browser request.